Melt spinning serves to fabricate metal ribbons or tapes, mostly from alloys which, if produced by techniques other than melt spinning, are brittle. By melt spinning, however, they can be produced as ductile and, thus, machinable ribbons or tapes, since they are a solidified liquid like glass. Therefore, they are also referred to as "metallic glasses".
In the book "Metallic Glasses--Papers presented at a Seminar of the Materials Science Division of the American Society for Metals, Sept. 18 and 19, 1976", American Society for Metals, Ohio, Jan. 1978, pages 36 to 38, an apparatus for producing metallic glasses in ribbon form is described in connection with the schematic of FIG. 1 on page 38.
In that process, a jet of molten alloy is forced out of a crucible onto the side surface of a metal drum of high thermal conductivity rotating at a high circumferential velocity, the crucible being disposed above the metal drum at a distance approximately equal to the metal drum diameter. After solidification of the melt, the ribbon separates from the metal drum.
In the journal "Materials Science and Engineering", Vol. 49, 1985, pages 185 to 191, a method of forming a ribbon helix from a metallic glass is described in connection with FIG. 1 on page 185. A jet of the molten alloy is impinged at an angle different from 90.degree. onto the side surface of a metal drum of high thermal conductivity rotating at a high circumferential velocity, and the helix formed, after becoming detached from the metal drum, is guided around the rear side surface facing away from the impingement side surface.
As experiments by the inventors have shown, a main problem in the fabrication of the above-mentioned helical ribbons and, consequently, in the formation of rings of uniform thickness and width to be cut therefrom consists in the following: It must be ensured that during the very short time that the alloy is quenched on the metal drum, separates from the metal drum, and coils to form the helix, the individual windings of the helix are not overstretched by plastic deformation or not bonded together, which would result in a sort of ribbon clew that would be difficult to separate into the individual rings. This problem arises particularly during the formation of rings from an active brazing alloy which is brittle without the use of the melt-spinning technique.